1. Field of the Invention
The present invention relates to an apparatus for pressing a prober plate on an electrode-forming portion of a liquid crystal panel or other circuit boards for inspection.
2. Description of Related Art
Conventionally, in order to inspect a liquid crystal panel, circuit substrate, or the like (hereinafter referred to as inspection substrate), an apparatus for pressing a prober on an electrode-forming portion of the inspection substrate has been used. Generally, in the inspection, such a probe needle as disclosed in the published Japanese Patent Applications No. 7-94559 and No. 9-281139, for example, have been widely used.
However, such probe needle is plated with gold, so that it is quite delicate and expensive. For this reason, as a replacement for a probe needle, a probe plate disclosed in the published Japanese Patent Applications No. 7-240443 and No. 10-123176, which comprises electrodes formed on an insulating substrate, has received widespread attention. Recently, a long length of a probe plate has been developing.
However, as shown in FIG. 9, such a probe plate comprises, as an insulating substrate, a resin film 1 having a plurality of electrodes 2 with fine pitches of 70 xcexcm or less. When the probe is pressed by a pressure head to be brought into intimate contact with a electrode-forming portion 4 of an inspection substrate 3 as shown in FIG. 8, the probe has to be pressed at a relatively high pressure so that the probe can easily be damaged. On the other hand, where the probe is pressed at a low pressure, insufficient contact pressure degrades the reliability of a contact between the probe and the electrodes 5 on the inspection substrate 3, which causes a serious problem in inspection.
An object of the present invention is to provide an apparatus and method for pressing a prober at a sufficient pressure without injury to the prober, and thereby increasing the reliability of a contact between an inspection substrate and an electrode.
Specifically, in the apparatus and method for pressing a prober according to the present invention, a prober is pressed on an electrode-forming portion of an inspection substrate by a press having a plurality of pressure heads. The term xe2x80x9cproberxe2x80x9d used in this specification means an electrode that takes an electric current from a predetermined part of a test sample, and it is generally called probe.
Since the apparatus for pressing a prober according to the present invention comprises a plurality of split pressure heads, predetermined portions of the prober, each of which are uniform in size, are pressed by the heads respectively, and an intimate contact between the prober and the inspection substrate is thereby ensured.